Doped polyacetylene, (CH).sub.x, has generated a great deal of interest as an electrode material for low cost, lightweight organic batteries with potential for high power densities. See, e.g., MacDiarmid et al., Nato Conf. Ser., Molec. Met., 6 (1), 161 (1982); Chiang, Polymer, 22, 1454 (1981); P. J. Nigrey et al., J. Electrochem. Soc., 129, 1270 (1982); T. Nagatomo et al., Jap. J. Appl. Phys., 22, L275 (1983); R. H. Baughman et al., Chem. Rev., 82, 209 (1982); J. Simionescu et al., Prog. Polym. Sci., 8, 133 (1982); and Masuda et al., Acct. Chem. Res., 17, 51 (1984); which disclosures are incorporated by reference herein. While polyacetylene can be doped to a metallic state (-1200 S/cm), its intractability, O.sub.2 sensitivity, and long-term instability pose severe problems in processing the material on a commercial scale.
In programs of synthesis directed toward conductive materials having improved stability and processibility, polyacetylene derivatives have been prepared, e.g., poly-(trimethylsilylacetylene) (PTMSA) --C(Si(CH.sub.3).sub.3).dbd.CH)--. PTMSA has been reported previously (MW 10000), Okano et al., Polym. Preprints Jap., 31, 1189 (1982), or its duplicate J. Polym. Sci., Polym. Chem. Ed., 22, 1603 (1984); Voronkov et al., J. Polym. Sci., Polym. Chem. Ed., 18, 53 (1980); and WO 8301905 A1 (9/6/83) to Mitsubishi Chemical Ind. Co., Ltd, Chem. Abs., 99: 159660f. However, polymers of high molecular weights were not obtained using the methods and catalysts of the prior art.
A large number of catalyst systems were surveyed in this work for activity in polymerization of trimethylsilylacetylene, a commercially available compound. Of the wide variety of previously known alkyne polymerization catalysts evaluated, only the tungsten-based catalysts, WCl.sub.6.Ph.sub.4 Sn used by the prior art and (W(CO).sub.6 /hr/CCl.sub.4, gave significant amounts of PTMSA. These were not, however, satisfactory in all respects. The preparation of soluble PTMSA with WCl.sub.6.Ph.sub.4 Sn and (W(CO).sub.6 /CCl.sub.4 /hr suffered from low and irreproducible conversions, particularly in large scale (10 g) runs. Attempts to increase conversion by use of additional catalyst aliquots were only marginally successful. See the last two entries in Table 1. It proved difficult to separate the resulting polymer from catalyst residues and Sn by-products. Okano et al. and this work were unable despite several attempts, to duplicate the results of Voronkov et al., that PTMSA can be obtained using MoCl.sub.5 as a catalyst. Their procedure yields only low molecular weight liquid oligomers of TMSA, which are of no value for conductive polymer applications.
These difficulties, as well as the large amount of insoluble material formed in previous approaches, spurred efforts to develop improved methods of PTMSA synthesis.
In this regard, methods for preparing a variety of other related polymers are also inapplicable to the problem of polymerizing TMSA and related monomers and/or comonomers to the high molecular weights desirable for important applications. For example, U.S. Pat. No. 3,198,766 employs a combination of metallic catalysts in the polymerization of unsaturated organic compounds including acetylene with organosilicon compounds containing at least one Si-H bond. U.S. Pat. Nos. 3,699,140 and 3,758,541 involve the preparation of organosilicon compounds containing acetylenic unsaturation. U.S. Pat. No. 3,878,263 involves the preparation of acrylate-functional polysiloxane polymers. U.S. Pat. No. 4,472,562 relates to stabilized polyorganosiloxane compositions.
The catalyst WCl.sub.6 +n-RLi, per se, is known, e.g., for metathetic cycloolefin polymerization. See, e.g., B. A. Dolgoplosk, et al., Eur. Polym. J., 15, 237 (1979). However, this catalyst has never before been used for polymerization of acetylenic compounds.